1997 exp sport 4x4 manual. during start, entire power syptem goes dead during crank. very erratic..may go 2-3 days with no problem. batt is 4 years old and i do suspect it could have an internal problem that only shows up occassionally. batery reads 12.5 v when off and 14.4 when running. specific gravity checks in low green, all cells.

when you release ignition out of crank, you can hear a relay click, and then power is back on. radio and clock reset, just as though you had diconnected battery. sometimes you can immediately attemp restart and it will start. always, if you wait a few minutes, it will restart. i have yet to check connections at starter. starter is original, as far as i know. will pull starter and dissy to check guts to see how it looks. only other items are solendoid and relay, but the starter always engages and the engine starts to turn when the power just appears to short out the battery supply, so relay and solendoid are doing there job it appears. i suspect bad starter or battery???

any one had similiar problem. i hate to just start chaning ou parts on an guess.

THX!

 

I have a 94 Sport that's doing something similar but not the starting problem. When I first got the truck, the radio would reset about once or twice a year. Never thought too much about it.

Over the last month it's gotten really bad. Almost resets on a daily basis. Doesn't lose the station memories, just the clock and bass and treble settings reset. I've tried turning the radio off before I shut the truck off so there's no "surge" of any sorts when I re-start the truck. Didn't make a lick of a difference.

 

My Explorer and my BII have behaved the exact same way, and each time it's been a bad connection at the battery post. Usually the bolts were corroded so I couldn't tighten them up or the "clamps" had stretched so they no longer fit snugly on the battery post or similar. 1st thing I'd have you check is the battery cables and connections.

 

thanks mr shorty..forgot to mention i cleaned the batt post and terminals, but will double check again. bad connection at battery would cause loss of power to entire truck when the starter is engaged, due to high amps needed during start.

(i need to do the same at all connections...starter relay, soleniod and starter..but a bad connection at these places should not shut down power to entire truck, just cause starter not to work...agree?).

i do wonder if the starter has an intrernal short in it, that only shows up when the starter stops at or near that bad spot??? ..THX

 

Don't forget to check ground cables.

 

Check ALL cables they are know to corrode inside the rubber casing, causing these type of symtoms., agravating yes....

 

check the spade connector on the starter.

it is a known corrosion point.

 

Thanks all...will dig into it this weekend and post what I find!

 

OK, just checked the battery again. All cells read in low green specific gravity. Polished both terminals and the inside ends of batt cables (they looked OK before, now thery look like new. Pulled the starter and dissy'd it. It looked fine. All brushes OK with plenty of lenght (I had hoped to see one of them worn to a nub, cuasing the starter to short against holders..no luck.) Lubricated all bushings, shaft journals and panetary gears and re-assy'd. All connections are perfect. (Note this is a 4wd...one of the most difficult starters I have ever removed!). All back together and time will tell. I expect it to repeat the problem I had before, as I found nothing wrong.

Remember, my probem is the entire power to truck drops out, during start and AFTER the starter has engaged and started turning the engine, just before it fires off! Although this battery checks good, it was in the truck when I bought it 3 years ago and I have no idea how old it is.
I have seen batteries check good when not under a load, but break down under a load.
About all that is left is the battery and the starter solenoid relay.

THX all...will let you know where I end up!

 

Can you get the battery somewhere to have a load(200-400amp) put on it, that will bleed of any surface charge and check the true condition of the cells/plates.
Did you check those cables for internal resistance?, they are known to corrode inside the rubber casing.

 

both excellent ideas. i just put a brand new diehard gold in the wifes 97 EXP 2 weeks ago. i should swap them out tomorrow and see what happens. if i get immediate and drastic improvement, time to get a battery. i did look at ll the cable ends for the condition you described, and they look good as far as one can see, BUT i am aware a problem could be further under the insulation. the mystery is it will start strong and fine 30 times in row, and then....it acts just like something shorts and drains all voltage to entire truck. THX!

 

Corrusion inside the cable under the insulation is not uncommon.

 

Update...apologies For Delay In Update. The Problem Was The Battery. Despite It Reading 12.7 Volts And Having An Excellent Specific Gravity Reading, It Would Break Down Under The Starting Load. I Have Seen This Once Before In A Battery. The Terminal Connection Was Loose And Cracked Inside The Battery!